Locomotive and machine works



. G. J. MELLIN. COMPOUNDv $TEAM ENGINE.

No. 557,135. 3 Patented Mar. 31, 1896 E a a 1 F i \\1 I I 3. a. I a'llllvll t r dbl ///J a. 6L 2 v on! b s I 5 o 5/ bl yu I m y WITNESSES 1 INVENTEIR- Aypncw asmglgmguui'dumawisnmmmnc.

NITED STATES I ATENT FricE.

CARL J. MELLIN, OF RICHMOND, VIRGINIA, ASSIGNOR TO THE RICHMOND LOCOMOTIVE AND MACHINE WORKS, OF SAME PLACE.

COMPOUND STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 557,135, dated March 31, 1896.

Application filed March 28, 1894. Serial No. 505,408. (No model.)

To all whom it may concern:

Be it known that I, CARL J. MELLIN, a citizen of the United States, and a resident of Richmond, in the county of Henrico and State of Virginia, have invented certain new and useful Improvements in Compound Steam- Engines, of which the following is a specification.

My invention relates to intercepting-valves for temporarily working high steam direct in both cylinders of a compound engine at starting and to emergency-valves whereby the direct action of the live steam may be continued longer in the low-pressure cylinder at starting and the change from compound to direct action may be readily effected while working, as often required in the case of a locomotiveengine, on steep grades.

The invention consists of the hereinafterdescribed improvements in theintercepting and emergency valves, reference being made to the accompanying drawings, in which- Figure 1 is a longitudinal sectional elevation of the intercepting-valve, said valve being open, as when the engine is working in the compound system, the emergency-valve being omitted. Fig. 2 is a similar section with modifications of the dash-pot and live-steam valve, the intercepting-valve being closed, as for working live steam direct in both cylinders. Fig. 3 is a longitudinal section of the intercepting and emergency valves, the intercepting-valve being open for compound action; and Fig. 4 is a similar section showing a slight modification of the interceptingvalve.

The valve-case a is connected inthe steampassage by which the exhaust-steam from the high-pressure cylinder goes to the low-pres sure cylinder, so that the BXllLllSlJ-StGELIILiS received in the valve chamber 1), between which and the outlet 0 to the low-pressure cylinder is the intercepting-valve d, which closes in the recessed seat 6 when live steam is to be worked in both cylinders.

f is a small live-steam pipe always open to the live steam when the throttle-valve is open, said pipe preferably being a branch of the main steam-pipe communicating therewith between the throttle-valve and the high-pressure cylinder. This pipe admits live steam to the piston-valve g, which being fitted in a small bore Z in the hub of the cover h of the intercepting-valve case, parallel with it and its guiding-stem 'i and so as to bear against said valve, receives the live steam on the shoulderj for closing the intercepting-valve when relieved of the pressure of exhauststeam on the other side and for opening ports 7a to enter the low-pressure cylinders when the interceptingvalve is so closed. This valve g has a stem g of smaller size in the smaller bore l on the other side of the steam space m, so that in case live-steam pressure may happen to rise too high in the low-pressure cylinder the pressure on the greater area of the inner end of 9 will overbalance the pressure on shoulder j and close ports and reduce the pressure.

In Fig. 2 I represent a modification of this 70 piston-valve, which consists in reducing the part g for some length back of shoulder j to a small connecting member, as 9 with a shoulder g opposing shoulder j, the object of which is to provide larger steamway with a valve of a given size whereby smaller valves may be used, which is desirable and which is the purpose of the arrangement of this valve independently of the stem of the interceptingvalve instead of arranging it as in my Patent No. 519,407, dated May S, 1894, also in my pending application filed March 19, 1894, Serial No. 504,179.

The distance of the shoulder g from shoulderj is to be such that said shoulder g will not advance beyond the seat g when said valve is open. Two or more of these valves may be used, being distributed around the stem '5, as preferred. On the other or inside of the intercepting-valve (Z and at the opposite side of the steam-receiving chamber 1) I provide a dash-pot cylinder at on a suitable extension 0 of said valve and provide a stationary piston p on the cover q of the valvecase, coaoting with said cylinder for checking 5 the closing of the intercepting-valve to avoid shocks, the exterior of said dash-pot cylinder being also a piston 0, working in a suitablybored partition for a means of more positively closing the intercepting-valve and for con- 10o trolling the exhaust of the high-pressure cylinder when working steam direct in both cylinders. The dash-pot is alike available in this location whether an emergency-valve, as t, is used or not, the purpose of which, as is well known, is to continue the action of live steam direct in the low-pressure cylinder longer at starting and to change from the compound action to direct action while running.

In Fig. 3 the emergency-valve t is located in a chamber of the piston 19. In Fig. 4 it is located in a bush a, fitted in said chamber through an opening in cover q and secured by its cover 7). It is entered in said chamber of Fig. 3 through a hole in the head of the piston closed by a plug cl.

In Figs. 1 and 2 the emergency-valve is omit-ted, said valve being only represented in Figs. 3 and i. This valve has its seat at w, Figs. 3 and 4, to open for the escape of the high-pressure exhaust-steam from chamber a; into chamber y, from which it may discharge by any suitable passage. The said emergency-valve has a piston z, behind which steam is admitted through the pipe a at the will of the engineer for opening it, and the coiled spring I) closes it when the engineer shuts oii steam from pipe at.

hen the emergency valve opens and pressure falls in chamber 00 thereby, the pressure of steam in chamber 1) on piston c reinforces the pressure of live steam 011 shoulder j for prompt closing of valve (1.

\Vhen the dash-pot cylinder-piston 0 passes partition .9 as the intercepting-valve closes, it opens communication from chamber 1) into chamber as, which occurs at the moment valve (Z enters recess 6 of its seat, or a little later, so that live-steam may not escape from chamber 0 through the emergency-valve, as would be the case if communication were opened earlier into chamber a.

I am aware of the patent to Von Berries, No. 361,475, in which there is a small socket on the side of the steam-receiving chamber opposite to the valve in which the stem of the valve, only adapted for a guide to the valve, works, and I make no claim to such device, the said stem and socket being incapable of the function of a dash-pot, which when properly constructed for practical use always has free inlet of vapor to the cylinder in front of the piston when the piston is retracted, to be trapped in and compressed when the dashpot closes, and to have the functions of a dash-pot the dimensions of the parts must be commensurate with the work to be performed, which is not the case with the guide of the said patent, nor is it represented as a dashpot in the patent.

I claim 1. The combination with the intercepting disk-valve having the central supporting and guiding stem, of one or more livesteam reducing piston -valves adapted for closing said intercepting-valve and admitting live steam to the low-pressure cylinder, said piston valve or valves located in a line or lines parallel with but not in the axis of the intercepting-valve stem.

2. The combination with the interceptingvalve of a live steam reducing piston-valve adapted for closing said intercepting-valve, and admitting live steam to the low-pressure cylinder, said piston-valve having the differential opposing heads subject to the live steam, and the reduced intermediate coacting section, and placed independently of, but parallel with the stem of the intercepting-valve substantially as described.

3. The combination with the interceptingvalve of a live-steam reducing piston-valve adapted for closing said intercepting-valve and admitting live steam to the low-pressure eylinder,anda dash-pot, said dash-potlocated on the side of the chamber receiving the steam from the high-pressure cylinder opposite to said valve and forming a valve in the highpressure exhaust-passage substantially as described.

4. The combination with the interceptingvalve of a live-steam reducing piston-valve adapted for closing said intercepting-valve and admitting live steam to the low-pressure cylinder, and the dash-pot, said dash-pot located on the side of the chamber receiving the steam from the high-pressure cylinder opposite to said valve, said dash-pot consisting of the cylinder formed on the stem of the intercepting-valve, and the piston on the cover of the valve-case substantially as described.

5. The combination with the interceptingvalve, of the dash-pot located on the side of the chamber receiving the steam from the high-pressure cylinder opposite to the intercepting-valve, and consisting of the cylinder formed 011 the stem of the intercepting-valve, and the piston on the cover of said valve-case, said dash-pot adapted to control the direct exhaust from the high-pressure cylinder substantially as described.

6. The combination with the interceptingvalve, and the emergency-valve, of the dashpot located on the side of the chamber receiving the steam from the high-pressure cylinder opposite to the intercepting-valve, and consisting of the cylinder formed on the stem of the intercepting-valve, and the piston on the cover of the valve-case, said dash-pot adapted to control the exhaust through the emergencyvalve substantially as described.

7. The combination with the interceptingvalve and the emergency-valve, of the dashpot located on the side of the chamber receiving the steam from the high-pressure cylinder opposite to the intercepting-valve, and consisting of the cylinder formed on the stem of the intercepting-valve, and the piston formed on a bush of the cover of the valve-case, said dash-pot adapted to control the emergencyexhaust, and the emergency-valve located in said bush substantially as described.

8. The combination with the intercepting- Valve and the emergency-valve, of the dashlocatedinabushinserted in the dash-pot bush 1o pot located on the side of the chamber receivsubstantially as described.

ing the steam from the high-pressure cylinder Signed at Richmond, in the county of Henopposite to the intercepting-va1ve,of the dashrice and State of Virginia, this 26th day of pot consisting of the cylinder formed on the March, A. D. 1894.

stem of the intercepting-valve, and the piston O. J. MELLIN. formed on a bush of the cover of the valve- Witnesses: case, said dash-pot'adapted to control the W. O. GRAY,

emergency-exhaust, andthe emergency-valve W. A. LOVING. 

